Li Mingda, the Princess of Jinyang in the Tang Dynasty, carries a mysterious jade pendant and unexpectedly travels through time into a modern university men's dormitory. There, she is taken in by Lin Yuan, who is going through a painful breakup, and his roommates. These seemingly useless young men suddenly become full-time dads, fumbling their way through chaotic yet heartwarming everyday life as they raise a child. When a two-way passage between the two eras unexpectedly unlocks, rare treasures from the Tang Dynasty and modern inventions begin traveling in both directions. While protecting their adorable little princess, the young men also embark on a heartwarming journey to rewrite their destinies.